Study On Application Technology Of Tolclofos-Methyl And Its Compound In The Control Of Soil Borne Disease

This study gives a comparatively all-round explanation on the current application status of tolclofos-methyl both from home and abroad. According to the existing practical problems, this study is started from the prevention and cure spectrum of tolclofos-methyl, the combination of its compatible compound is selected and small range of test has been made, which provides theoretical and technical guidance for tolclofos-methyl.1. Fungistasis spectrum of tolclofos-methyl is obtained with perti-dish method, the result shows that it has higher activity to cotton Rhizoctonia rot peanut Sclerotinia, cole Sclerotinia rot, scallion white rot; it has certain activity to Pythium and Phytophthora under a higher concentration; The EC50 of fusarium which causes watermelon Fusarium blight is near to 100μg·mL-1, it has no practical applicable value.2. According to test result, complementary riddling is done to 12 kinds of fungicide, the best combination "tolclofos-methyl + thiram" is picked up by matrix method of fuzzy mathematics via potted planting and small area test, the secondary formula is "tolclofos-methyl + fenaminosulf, while the effect of "tolclofos-methyl + hymexaxzol" is poor. Among the 5 mixing proportions for testing, 35% of total content is converted and 120g is needed for per 667m2 , the effect for tolclofos-methyl: thiram =2:3 is the best, and the general preventative effect is the highest. So a content of 14% and 21% for tolclofos-methyl and thiram in preparation is determined.3. Synergized action determination is done by Sun's Method. The result of joint toxicity test shows: the Actual Toxicity Index (ATI) of tolclofos-methyl- thiram(2:3 )to Rhizoctonia solani is 4635.62, the ATI for Phtophthora nicotina is 549.93, the ATI for Fusarium oxysporum 2857.63, it shows that it has certain degree of synergistic action to Rhizoctonia solani, and it has obvious synergistic action to Phtophthora nicotina and Fusarium oxysporum. This compound has the fungicidal characteristic of tolclofos-methyl and thiram at the same time, it not only fetches up the defects of tolclofos-methyl to damping-off and Fusarium blight, but also overcomes, the deficiency of narrow prevention spectrum when they are used separately.4. A method of flow point measuring is adopted in the riddling of dispersant, orthogonal experimental design is employed in determination of proportion and dosage, fonnula of recipe is optimized. The ultimate formula is: 14% tolclofos-methyl, 21% thiram, NNO 5%, TX-10 2.5%, xanthan gum 0.2%, ethylene glycol 5%, muriate acid 3%, foam breaker FAG480 0.2%, tap water is added.5. High performance opposite phase liquid chromatography is adopted and sample is dissolved by methanol, methanol and water is taken as mobile phase, external standard method is used under 254nm to High Performance Liquid Chromatography (HPLC) separation and gauging of tolclofos-methyl and thiram of sample in which Hypersil C18 chromatographic column and ultraviolet detector is used. The linear equation and related coefficient oftolclofos-methyl and thiram in this analysis approach is y=290.9433x-615.99 r=0.9998, y=28.8944x-2769.9 r=0.9995 respectively. The standard deviation and coefficient of variation is 0.04037, 0.04278, 0.2868 % , 0.2028 % respectively. The recovery rate of tolclofos is 99.08%~100.21%, the average recovery rate is 99.49%; the recovery rate of thiram is 99.49%~100.09, the average recovery rate is 99.71%.6. Tolclofos-methyl and its compound is demonstratively experimented and technically popularized in more than 10 provinces of China in 2002-2004. The results shows that tolclofos-methyl is effective to sugarcene tiger-spot, annual bluegrass brown spot, white rot of garlic, it also can be employed in controlling soil borne disease for vegetables and traditional Chinese medicinal materials, such as Sclerotinia blight and Rhizoctonia rot . Tolclofos-methyl thiram compound has high prevention effect to eight kind of soil borne diseases, the effect in turn: cotton Rhizoctonia rot, Cucumber damping-off, capsicum Phytophthora blight, peanut Sclerotinia blight, scallion white rot, cole Sclerotinia rot, tobacco black stem and watermelon Fusarium blight. Field demonstrative popularization indicates 35% tolclofos-methyl- thiram Suspension Concentrate has obvious prevention effect to many common diseases, and it is very easy to use. From experiment to popularization, it shows that tolclofos-methyl · thiram is a kind of ideal fungicide, it has the features of high efficiency, broad-spectrum and security, it is worthwhile to popularize to large areas and it is very important to fill the market blank.